A gaming machine represented by a slot machine is highly popular among casino customers as a device that provides gambling that is easy to enjoy, and recent statistics also report that sales from gaming machines account for the majority of casino earnings. Initial slot machines were simple devices, wherein an inserted coin is received, a configured reel rotates and stops mechanically according to a handle operation, and win or lose is determined by a combination of symbols stopped on a single pay line. However, recent gaming machines, such as mechanical slot machines driven by a highly accurate physical reel via a computer controlled stepping motor, video slot machines that display a virtual reel on a display connected to a computer, and various gaming machines that apply similar technology to other casino games are quickly advancing. For the manufacturers that develop these gaming machines, an important theme is to provide an attractive game that strongly attracts casino customers as players, and improves the functionality of the gaming machine.
Under this type of background, in recent gaming machines, in order to make a change in game progress, after stopping a reel and forming a symbol array, which is the game result and outcome, a process is proposed that removes a portion of the symbols that configure the symbol array. For example, in Patent Document 1, an update process of the symbol array that forms a new symbol array is disclosed in addition to removing the symbols that configure a winning combination from the symbol array. According to this update process of a symbol array, the player can maintain hope for winning even after the reel has stopped, and the interest of the player in the game result can be maintained for a long period of time.